Generally, HVAC systems increase their overall efficiency by closely matching airflow to the refrigerant system capacity. Generally, lower airflows, such as approximately 325 cubic feet per minute (CFM) per ton, yield a higher seasonal energy efficiency ratio (SEER) due to lower electrical consumption of the fan. Open-loop airflow control systems, such as a permanent split capacitor to name one non-limiting example, lose airflow performance at high system static pressures. In order to avoid freezing of the heat exchanger, the open-loop control systems generally require higher airflows, such as approximately 400 CFM/ton, when filters clog, registers are obstructed, etc. There is, therefore, a need for a system and method to increase SEER efficiencies in an open-loop airflow control system while avoiding the possibility of a heat exchanger freezing.